Just be clear! No Unicorn!

Be gentle this be my first poly relationship. But been talking about it for awhile.

My wife(24f) and I (28m also demi if that matters) been talking about poly relationship for while. She tells her friend (24f), let's call her T, almost everything (when I mean everything it means). Know each other for a long time ever since my wife and I dated.. T even know we have been talk about poly. She want to be with me. Forming a V relationship.

Down to the part that I need help with.

My wife has feeling for T be in the closest about it to her. I believe it's the same going to other way as well. (Can't confirm yet) All stem over a birthday present they had planned for me long ago.

As demi I have fell for her, my wife knows and is perfectly approved of it. I have told T how I feel and she feels the same way towards me.

T want to be with me. The issue is T believe "if" something happens it would ruin my wife and her friendship.

Could this ruin there friendship?

If this formed a traid situation would it bring them closer?

Last one for my wife, would it be better to tell her that she has those feel towards T? Or keep them reserved?

Thanks in advance. Any good advice will help me.